JP5976873B1 - Elevator control device - Google Patents

Abstract

An object of the present invention is to detect an abnormal state of a semiconductor switching element mounted on an inverter device and to immediately perform a protection operation. An elevator control device according to an embodiment includes a voltage detection unit, a voltage prediction unit, an abnormality determination unit, and a protection operation unit. The voltage predicting unit 42 predicts a current pattern flowing through the IGBT 13a of the inverter device 13 based on the operation pattern of the car 4, and predicts the Vce voltage value of the IGBT 13a from the predicted current pattern. The voltage detector 41 detects the Vce voltage value of the IGBT 13a when the car 4 is in operation. The abnormality determining unit 43 compares the predicted value of Vce and the detected value to determine the abnormal state of the IGBT 13a. The protection operation unit 44 performs the protection operation of the IGBT 13a based on the determination result of the abnormality determination unit 43. [Selection] Figure 1

Description

  Embodiments described herein relate generally to an elevator control device including an inverter device.

  Usually, a semiconductor switching element represented by an IGBT (Insulated Gate Bipolar Transistor) is used for an inverter device of an elevator. In recent years, miniaturization of this type of semiconductor switching element has progressed, and accordingly, the short-circuit withstand capability has decreased, and the time from when a short-circuit current starts to flow to the element until destruction is very short. Accordingly, when an abnormality such as a short circuit occurs for some reason, it is necessary to immediately activate the protective operation.

Japanese Unexamined Patent Publication No. 7-7962 JP 2006-82933 A

  If an abnormality such as a short circuit occurs in the semiconductor switching element for some reason during operation of the elevator (car), the above-described inverter device does not operate normally and is in a very dangerous state.

  The problem to be solved by the present invention is to provide an elevator control device that can detect an abnormal state of a semiconductor switching element mounted on an inverter device and immediately activate a protective operation.

  An elevator control device according to an embodiment operates a car by driving an inverter device. The elevator control device includes voltage predicting means, voltage detecting means, abnormality determining means, and protective operation means.

  The voltage predicting means predicts a current pattern flowing in a semiconductor switching element mounted on the inverter device based on an operation pattern of the car, and a voltage between a collector and an emitter of the semiconductor switching element based on the predicted current pattern. Predict the value. The voltage detecting means detects a voltage value between a collector and an emitter of the semiconductor switching element during operation of the car. The abnormality determination unit compares the voltage value predicted by the voltage prediction unit with the voltage value detected by the voltage detection unit to determine an abnormal state of the semiconductor switching element. The protection operation unit performs the protection operation of the semiconductor switching element based on the determination result of the abnormality determination unit.

FIG. 1 is a diagram illustrating a configuration of an elevator control device according to the first embodiment. FIG. 2 is a diagram showing a state where the IGBT is short-circuited. FIG. 3 is a graph showing characteristics of the collector-emitter voltage Vce and the gate-emitter voltage Vge with respect to an increase in the IGBT collector current Ic. FIG. 4 is a diagram showing a change portion of the collector-emitter voltage Vce due to the IGBT collector current Ic. FIG. 5 is a diagram illustrating a configuration of an elevator control device according to the second embodiment. FIG. 6 is a diagram showing a schematic configuration of the IGBT. FIG. 7 is a diagram showing a state in which the solder joint between the ceramic substrate and the copper base has become brittle due to the aging use of the IGBT. FIG. 8 is a diagram showing characteristics of the collector current Ic and the collector-emitter voltage Vce with respect to the temperature rise of the IGBT. FIG. 9 is a diagram showing characteristics of the collector current Ic and the collector-emitter voltage Vce with respect to an increase in the IGBT gate-emitter voltage Vge. FIG. 10 is a diagram illustrating a configuration of an elevator control device according to the third embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of an elevator control device according to the first embodiment.

  The elevator includes a drive device 10 and an elevator control device 30. The drive device 10 includes a converter 11, a smoothing capacitor 12, and an inverter device 13, and supplies power necessary for driving the hoisting machine 2 in accordance with a drive instruction from the elevator control device 30.

  Note that the converter 11 converts an AC voltage supplied from the commercial power source 1 into a DC voltage. The commercial power source 1 is a three-phase AC power source. The smoothing capacitor 12 smoothes the ripple of the DC voltage converted by the converter 11. The inverter device 13 converts the DC voltage supplied from the converter 11 through the smoothing capacitor 12 into an AC voltage having an arbitrary frequency and voltage value by PWM (Pulse Width Modulation) control, and uses this as drive power to the hoist 2 To supply.

  The hoisting machine 2 is composed of a synchronous motor, and rotates by power supply from the driving device 10. A rope 3 is wound around the hoisting machine 2 through a sheave (not shown), and a rope 4 is connected to one end of the rope 3 and a counterweight 5 is connected to the other end. Thereby, with the rotation of the hoist 2, the car 4 and the counterweight 5 are lifted and lowered via the rope 3.

  The inverter device 13 provided in the drive system of the elevator incorporates at least one set of IGBT (semiconductor switching element) 13a and a diode (rectifier element) 13b connected in reverse parallel to the IGBT 13a as circuit elements. .

  The elevator control device 30 is also referred to as a “control panel” and is a part that controls the entire elevator. The elevator control device 30 includes a voltage detection unit 41, a voltage prediction unit 42, an abnormality determination unit 43, and a protection operation unit 44 as functions for detecting an abnormal state of the IGBT 13a.

  The voltage detector 41 detects the collector-emitter voltage Vce of the IGBT 13a to be monitored during operation of the car 4.

  The voltage predicting unit 42 predicts a current pattern flowing through the IGBT 13a based on the operation pattern of the car 4, and predicts a collector-emitter voltage Vce of the IGBT 13a from the predicted current pattern. The driving pattern includes the load on the car 4 and the destination floor. That is, the electric power necessary for driving the inverter device 13 is obtained from the load obtained as the operation pattern of the car 4 and the destination floor before the operation, and the current and voltage flowing through the IGBT 13a are predicted from the electric power.

  The abnormality determination unit 43 compares the collector-emitter voltage Vce predicted by the voltage prediction unit 42 with the collector-emitter voltage Vce detected by the voltage detection unit 41 to determine the abnormal state of the IGBT 13a. In this case, if the difference between the two voltage values is equal to or greater than a preset value, it is determined that the IGBT 13a is in a short circuit state.

  The protection operation unit 44 performs the protection operation of the IGBT 13a based on the determination result of the abnormality determination unit 43. Specifically, when the abnormality determination unit 43 determines that the IGBT 13a is short-circuited, the protection operation unit 44 immediately stops the car 4 at the nearest floor and drives the inverter device 13. Stop.

  Next, a method for detecting the short circuit state of the IGBT 13a will be described.

  As shown in FIG. 2, when the IGBT 13a is short-circuited, a large collector current Ic (high di / dt) flows as a short-circuit current. At this time, a phenomenon occurs in which the gate-emitter voltage Vge rises through the stray capacitance of the element. As shown in FIGS. 3 and 4, the collector-emitter voltage Vce at the time of energization also changes as the collector current Ic increases.

  Here, it is possible to predict an energization current pattern for the IGBT 13a from the loading load and destination floor of the car 4, and it is also possible to predict a voltage change of Vce from the energization current. When a short circuit occurs in the IGBT 13a due to some trouble, a large collector current Ic flows through the IGBT 13a as described above, so that the voltage value of Vce also changes. Therefore, if the change is detected, it is possible to detect that the IGBT 13a is short-circuited.

  Therefore, the voltage predicting unit 42 shown in FIG. 1 predicts the current pattern flowing through the IGBT 13a from the operation pattern (loading load and destination floor) at that time before the operation of the car 4, and the collector of the IGBT 13a from the current pattern. The emitter-to-emitter voltage Vce is predicted and given to the abnormality determination unit 43. As a prediction method, for example, there is a method in which a relational expression between a current and a voltage flowing in the IGBT 13a is prepared in advance for each operation pattern of the car 4, and prediction is performed according to the relational expression.

  On the other hand, when the car 4 is operated, the voltage detection unit 41 detects the collector-emitter voltage Vce of the IGBT 13 a and applies it to the abnormality determination unit 43. The abnormality determination unit 43 compares the predicted value of Vce given from the voltage prediction unit 42 with the detection value of Vce given from the voltage detection unit 41.

  In this case, if the IGBT 13a is in a normal state, the predicted value and the detected value are the same value or approximate values. If the IGBT 13a is in an abnormal state, the predicted value and the detected value are different. Therefore, the abnormality determining unit 43 obtains a difference between the predicted value and the detected value, and determines that the IGBT 13a is in an abnormal state, that is, a short circuit state, if the difference is equal to or greater than a preset value.

  When the abnormality determination unit 43 determines that the IGBT 13a is in a short-circuit state, the protection operation unit 44 immediately stops the car 4 to the nearest floor as a protection operation, and stops driving the inverter device 13. Thereby, before the IGBT 13a is damaged, the drive of the inverter device 13 can be stopped, and the operation of the car 4 can be stopped to ensure the safety of passengers.

  In this way, by predicting the voltage value of Vce from the driving pattern of the car 4, and comparing the predicted voltage value with the voltage value detected during driving, the abnormal state of the IGBT 13a can be detected and short-circuited. If it is, the protection operation can be immediately performed.

(Second Embodiment)
Next, a second embodiment will be described.

  In the second embodiment, in addition to the configuration of the first embodiment, a function of correcting the predicted value of Vce according to the deterioration state of the IGBT 13a to be monitored is provided.

  FIG. 5 is a diagram illustrating a configuration of an elevator control device according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same part as the structure of FIG. 1 in the said 1st Embodiment, and the description shall be abbreviate | omitted.

  In the configuration of FIG. 5, the difference from FIG. 1 is that the elevator control device 21 is provided with a correction unit 45. The correction unit 27 determines the deterioration state of the IGBT 13a to be monitored, and corrects the voltage value of Vce predicted by the voltage prediction unit 42 according to the deterioration state.

  FIG. 6 is a schematic configuration diagram of the IGBT 14a.

  The IGBT chip 51 made of silicon is connected to a main electrode formed on the ceramic substrate 53 via a bonding wire 52. The ceramic substrate 53 is joined to the copper base 55 for heat dissipation with solder 54. A heat radiator 56 is provided under the copper base 55, and heat generated in the IGBT chip 51 is released to the heat radiator 56 through the copper base 55, which is a heat radiating plate, as indicated by arrows.

  Here, when the IGBT 13a repeatedly generates heat / pauses due to the operation of the elevator and the temperature variation occurs in the copper base 55, stress is applied to the solder 54 at the joint due to the difference in thermal expansion coefficient between the ceramic substrate 53 and the copper base 55. There is a problem that embrittlement (crack) occurs.

  The state at this time is shown in FIG. With the aging of the IGBT 13a, when the embrittlement of the solder 54 that joins the ceramic substrate 53 and the copper base 55 becomes severe, the heat dissipation performance is remarkably lowered, the junction temperature is increased, and the IGBT chip 1 is heated. fall into disrepair. In particular, when the elevator is used repeatedly for rapid acceleration / stop, the thermal stress applied to the IGBT 13a becomes large, and the above phenomenon appears remarkably.

  If the current applied to the IGBT 13a is constant, the collector-emitter voltage Vce varies depending on the temperature Tj of the IGBT chip 51 as shown in FIG. That is, as the temperature Tj increases, the voltage value of Vce increases.

  Therefore, the deterioration state is determined by operating the car 4 under predetermined conditions during maintenance and inspection or by remote operation from a monitoring center (not shown) and comparing the voltage change of the IGBT 13a with the initial value.

  The “predetermined condition” is to drive in a state where there is no load fluctuation. Specifically, the car 4 is in an empty state (this is referred to as “no-load: NL”), and at a constant speed in the up direction or Driving in the down direction. When the car 4 is in the NL state and is operated at a constant speed, a constant collector current Ic flows through the IGBT 13a. Therefore, if the collector-emitter voltage Vce at that time is measured, the degree of deterioration can be found by comparison with the initial value.

  The correction unit 45 shown in FIG. 5 determines the deterioration state of the IGBT 13a from the voltage value of Vce detected when the IGBT 13a is energized under a certain condition as described above, and the voltage prediction unit 42 according to the deterioration state. The voltage value of Vce predicted by is corrected. In this case, the voltage characteristic of Vce is corrected so as to increase the voltage value as the deterioration of the IGBT 13a progresses. The abnormality determination unit 43 compares the predicted value of Vce obtained from the corrected voltage characteristics with the detected value of Vce during operation, and performs abnormality determination of the IGBT 14a.

(Modification)
In the second embodiment, the deterioration state of the IGBT 13a is determined from the voltage value of Vce detected when the IGBT 13a is energized under a certain condition. However, the deterioration state is also determined by measuring the voltage value of Vge. Is possible.

  The characteristic diagram shown in FIG. 8 is data of Vge = 15V. Even at the temperature of the same IGBT element, the value of the collector-emitter voltage Vce varies depending on the value of Vge as shown in FIG. In this example, the characteristics of Vce when Vge = 20V, 15V, 12V, 10V, and 8V are changed are shown.

  Since the gate circuit of the IGBT element is mounted with an article that deteriorates characteristics such as an aluminum electrolytic capacitor, the collector-emitter voltage Vge may change over time. Also, since Vge varies depending on the load condition (energization current), measure Vge when the IGBT 13a is energized under certain conditions (for example, operation from the first floor to the fourth floor when no one gets on). If compared with the initial value, the deterioration state of the IGBT 13a can be determined from the variation.

  The correction unit 45 shown in FIG. 5 determines the deterioration state of the IGBT 13a from the voltage value of Vge detected when the IGBT 13a is energized under a certain condition as described above, and the voltage prediction unit 42 according to the deterioration state. The voltage value of Vce predicted by is corrected. In this case, the voltage characteristic of Vce is corrected so as to increase the voltage value as the deterioration of the IGBT 13a progresses. The abnormality determination unit 43 compares the predicted value of Vce obtained from the corrected voltage characteristics with the detected value of Vce during operation, and performs abnormality determination of the IGBT 14a.

  Thus, by correcting the voltage value predicted by the voltage predicting unit 42 according to the deterioration state of the IGBT 13a to be monitored, the abnormal state of the IGBT 13a can be determined more accurately, and immediately when short-circuited It is possible to shift to the protection operation.

(Third embodiment)
Next, a third embodiment will be described.

  In the third embodiment, in addition to the configuration of the first embodiment, a function for correcting the predicted value of Vce in consideration of the temperature condition of the IGBT 13a to be monitored is provided.

  FIG. 10 is a diagram illustrating a configuration of an elevator control device according to the third embodiment. In addition, the same code | symbol is attached | subjected to the same part as the structure of FIG. 1 in the said 1st Embodiment, and the description shall be abbreviate | omitted.

  In the configuration of FIG. 10, the difference from FIG. 1 is that the elevator control device 21 is provided with a temperature detection unit 46 and a correction unit 47. The temperature detection unit 46 detects the temperature around the IGBT 13a to be monitored. The periphery of the IGBT 13a includes the periphery of the inverter device 13 on which the IGBT 13a is mounted. The correction unit 47 predicts the junction temperature increase state of the IGBT 13a from the temperature detected by the temperature detection unit 46, and corrects the voltage value of Vce predicted by the voltage prediction unit 42 in accordance with the junction temperature increase state.

  That is, the temperature around the inverter device 13 on which the IGBT 13a is mounted is not always constant, and varies depending on the operating rate and season of the elevator. In particular, the temperature difference is noticeable between summer and winter. Since the junction temperature of the IGBT 13a used in the inverter device 13 is also affected by the ambient temperature, it is considered that the voltage characteristic of Vce fluctuates.

  Therefore, a temperature sensor (not shown) is installed near the inverter device 13, and the temperature measured by the temperature sensor is detected by the temperature detection unit 46. The correction unit 47 corrects the voltage value of Vce predicted by the voltage prediction unit 42 in consideration of the temperature detected by the temperature detection unit 46.

  For example, assume that the ambient temperature of the IGBT 13a is 5 degrees higher than the temperature measured at the initial stage. In such a case, the voltage characteristic of Vce is corrected so as to increase the voltage value by 5 degrees of the temperature difference. As a result, the abnormality determination unit 43 determines the abnormality of the IGBT 14a by comparing the predicted value of Vce obtained from the corrected voltage characteristics with the detected value of Vce during operation.

(Modification)
In the third embodiment, the Vce voltage characteristic is corrected in consideration of the ambient temperature of the IGBT 13a. However, the Vce voltage characteristic may be corrected in consideration of the internal temperature of the IGBT 13a.

  That is, the time constant of cooling differs between summer and winter, and a difference occurs in the temperature change of the IGBT chip during energization. For example, when heat is accumulated due to the energization from the front, the internal temperature becomes high.

  Therefore, the internal temperature of the IGBT 13a is measured by a temperature sensor (not shown), and the temperature is detected by the temperature detector 46. The correction unit 47 corrects the voltage value of Vce predicted by the voltage prediction unit 42 in consideration of the temperature detected by the temperature detection unit 46.

  For example, it is assumed that the internal temperature of the IGBT 13a is 5 degrees higher than the temperature measured at the initial stage. In such a case, the voltage characteristic of Vce is corrected so as to increase the voltage value by 5 degrees of the temperature difference. As a result, the abnormality determination unit 43 determines the abnormality of the IGBT 14a by comparing the predicted value of Vce obtained from the corrected voltage characteristics with the detected value of Vce during operation.

  In this way, by correcting the predicted value of Vce in consideration of the temperature condition of the IGBT 13a to be monitored, the abnormal state of the IGBT 13a can be more accurately determined. can do.

  According to at least one embodiment described above, it is possible to provide an elevator control device that can detect an abnormal state of a semiconductor switching element mounted on an inverter device and immediately activate a protective operation.

  In addition, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Commercial power supply, 2 ... Hoisting machine, 3 ... Rope, 4 ... Car, 5 ... Counter weight, 10 ... Drive apparatus, 11 ... Converter, 12 ... Smoothing capacitor, 13 ... Inverter, 13a ... IGBT, 30 ... Elevator Control device 41 ... Voltage detection unit 42 ... Voltage prediction unit 43 ... Abnormality determination unit 44 ... Protection operation unit 45 ... Correction unit 46 ... Temperature detection unit 47 ... Correction unit 51 ... IGBT chip 52 ... Bonding wire, 53... Ceramic substrate, 54. Solder, 55. Copper base, 56.

Claims (7)

In an elevator control device that drives a car by driving an inverter device,
Predicting a current pattern flowing in a semiconductor switching element mounted on the inverter device based on an operation pattern of the car, and predicting a voltage value between a collector and an emitter of the semiconductor switching element from the predicted current pattern Means,
Voltage detecting means for detecting a voltage value between a collector and an emitter of the semiconductor switching element during operation of the car;
An abnormality determination unit that compares the voltage value predicted by the voltage prediction unit with the voltage value detected by the voltage detection unit to determine an abnormal state of the semiconductor switching element;
An elevator control apparatus comprising: a protection operation unit that performs a protection operation of the semiconductor switching element based on a determination result of the abnormality determination unit. The abnormality determination means is
Determining that the semiconductor switching element is in a short-circuited state when the difference between the voltage value predicted by the voltage predicting means and the voltage value detected by the voltage detecting means is greater than or equal to a preset value. The elevator control device according to claim 1, wherein: A deterioration state of the semiconductor switching element is determined from a comparison between a voltage value between the collector and the emitter when the semiconductor switching element is energized under a certain condition and a preset initial value, and the voltage is determined according to the deterioration state. 2. The elevator control apparatus according to claim 1, further comprising correction means for correcting a voltage value predicted by the prediction means.   A deterioration state of the semiconductor switching element is determined from a comparison between a gate-emitter voltage value when the semiconductor switching element is energized under a certain condition and a preset initial value, and the voltage is determined according to the deterioration state. 2. The elevator control apparatus according to claim 1, further comprising correction means for correcting a voltage value predicted by the prediction means. Temperature detecting means for detecting the ambient temperature of the semiconductor switching element;
The semiconductor device further includes a correcting unit that predicts a rising state of the junction temperature of the semiconductor switching element from the temperature detected by the temperature detecting unit and corrects a voltage value predicted by the voltage predicting unit according to the rising state of the junction temperature. The elevator control device according to claim 1. Temperature detecting means for detecting a temperature change inside the semiconductor switching element;
2. The elevator control apparatus according to claim 1, further comprising a correcting unit that corrects a voltage value predicted by the voltage predicting unit in accordance with a temperature change detected by the temperature detecting unit.   The elevator control device according to claim 1, wherein the semiconductor switching element is an IGBT.

Images